using UnityEngine;

namespace DynamicFogAndMist
{
	[ExecuteInEditMode]
	public class DynamicFogOfWar : MonoBehaviour
	{
		public int fogOfWarTextureSize = 512;

		private Material fogMat;

		private static DynamicFogOfWar _instance;

		private Texture2D fogOfWarTexture;

		private Color32[] fogOfWarColorBuffer;

		public static DynamicFogOfWar instance
		{
			get
			{
				if (_instance == null)
				{
					_instance = Object.FindObjectOfType<DynamicFogOfWar>();
				}
				return _instance;
			}
		}

		private void OnEnable()
		{
			fogMat = GetComponent<MeshRenderer>().sharedMaterial;
			UpdateFogOfWarTexture();
		}

		private void OnDisable()
		{
			if (fogOfWarTexture != null)
			{
				Object.DestroyImmediate(fogOfWarTexture);
				fogOfWarTexture = null;
			}
		}

		private void Update()
		{
			fogMat.SetVector("_FogOfWarData", new Vector4(base.transform.position.x, base.transform.position.z, base.transform.localScale.x, base.transform.localScale.y));
		}

		private void UpdateFogOfWarTexture()
		{
			int scaledSize = GetScaledSize(fogOfWarTextureSize, 1f);
			fogOfWarTexture = new Texture2D(scaledSize, scaledSize, TextureFormat.ARGB32, false);
			fogOfWarTexture.hideFlags = HideFlags.DontSave;
			fogOfWarTexture.filterMode = FilterMode.Bilinear;
			fogOfWarTexture.wrapMode = TextureWrapMode.Clamp;
			fogMat.mainTexture = fogOfWarTexture;
			ResetFogOfWar();
		}

		private int GetScaledSize(int size, float factor)
		{
			size = (int)((float)size / factor);
			size /= 4;
			if (size < 1)
			{
				size = 1;
			}
			return size * 4;
		}

		public void SetFogOfWarAlpha(Vector3 worldPosition, float radius, float fogNewAlpha)
		{
			if (fogOfWarTexture == null)
			{
				return;
			}
			float num = (worldPosition.x - base.transform.position.x) / base.transform.localScale.x + 0.5f;
			if (num < 0f || num > 1f)
			{
				return;
			}
			float num2 = (worldPosition.z - base.transform.position.z) / base.transform.localScale.y + 0.5f;
			if (num2 < 0f || num2 > 1f)
			{
				return;
			}
			int width = fogOfWarTexture.width;
			int height = fogOfWarTexture.height;
			int num3 = (int)(num * (float)width);
			int num4 = (int)(num2 * (float)height);
			int num5 = num4 * width + num3;
			byte b = (byte)(fogNewAlpha * 255f);
			Color32 color = fogOfWarColorBuffer[num5];
			if (b == color.a)
			{
				return;
			}
			float num6 = radius / base.transform.localScale.y;
			int num7 = Mathf.FloorToInt((float)height * num6);
			for (int i = num4 - num7; i <= num4 + num7; i++)
			{
				if (i <= 0 || i >= height - 1)
				{
					continue;
				}
				for (int j = num3 - num7; j <= num3 + num7; j++)
				{
					if (j > 0 && j < width - 1)
					{
						int num8 = (int)Mathf.Sqrt((num4 - i) * (num4 - i) + (num3 - j) * (num3 - j));
						if (num8 <= num7)
						{
							num5 = i * width + j;
							Color32 color2 = fogOfWarColorBuffer[num5];
							color2.a = (byte)Mathf.Lerp((int)b, (int)color2.a, (float)num8 / (float)num7);
							fogOfWarColorBuffer[num5] = color2;
							fogOfWarTexture.SetPixel(j, i, color2);
						}
					}
				}
			}
			fogOfWarTexture.Apply();
		}

		public void ResetFogOfWar()
		{
			if (!(fogOfWarTexture == null))
			{
				int height = fogOfWarTexture.height;
				int width = fogOfWarTexture.width;
				int num = height * width;
				if (fogOfWarColorBuffer == null || fogOfWarColorBuffer.Length != num)
				{
					fogOfWarColorBuffer = new Color32[num];
				}
				Color32 color = new Color32(byte.MaxValue, byte.MaxValue, byte.MaxValue, byte.MaxValue);
				for (int i = 0; i < num; i++)
				{
					fogOfWarColorBuffer[i] = color;
				}
				fogOfWarTexture.SetPixels32(fogOfWarColorBuffer);
				fogOfWarTexture.Apply();
			}
		}

		public void SetFogOfWarTerrainBoundary(Terrain terrain, float borderWidth)
		{
			TerrainData terrainData = terrain.terrainData;
			int heightmapWidth = terrainData.heightmapWidth;
			int heightmapHeight = terrainData.heightmapHeight;
			float y = terrainData.size.y;
			float[,] heights = terrainData.GetHeights(0, 0, heightmapWidth, heightmapHeight);
			float num = base.transform.position.y - 1f;
			float num2 = base.transform.position.y + 10f;
			Vector3 vector = new Vector3((0f - terrainData.size.x) * 0.5f, 0f, (0f - terrainData.size.z) * 0.5f);
			for (int i = 0; i < heightmapHeight; i++)
			{
				for (int j = 0; j < heightmapWidth; j++)
				{
					float num3 = heights[i, j] * y + terrain.transform.position.y;
					if (num3 > num && num3 < num2)
					{
						Vector3 worldPosition = base.transform.position + vector + new Vector3(terrainData.size.x * ((float)j + 0.5f) / (float)heightmapWidth, 0f, terrainData.size.z * ((float)i + 0.5f) / (float)heightmapHeight);
						SetFogOfWarAlpha(worldPosition, borderWidth, 0f);
					}
				}
			}
		}
	}
}